Ethernet over copper: pros and cons

Ethernet over copper… should you use it as part of your network architecture or not? Know the pros and cons before making any decisions. Otherwise, you risk making a costly mistake.

The only PROs for Ethernet over Copper (EOC) are immediate cost savings and perhaps quick deployment, with the CONs being upgrade limitations, susceptibility to external influences (aging copper line plant and distance from CO), and interference.

For core/backbone links, I think fiber is a must in most cases as it gives you the ability to easily scale for increased bandwidths and different technologies (MPLS, CWDM, etc.) on top of it fiber. Distance limitations are at least 100 times greater than EOC in most cases (depending on interconnection technology). The only CON here is the cost of implementation, but the ROI over the next few years will be worth it.

EOC has its place as the last mile for users, from the wiring closet to servers, workstations, etc., where distance is much less of an issue and, in most cases, sources of interference can be limited using suitable wiring SOPs.

I had a chance to look at it from a service provider perspective and there is almost never a problem with a fiber connection other than hardware failure in the interconnect devices and even that is rare.

Therefore, the maintenance cost with fiber is typically little or non-existent, while for EOC routine maintenance is expected to ensure QoS or even basic service in some situations.

There is no doubt that copper technology is cost effective compared to fiber optics over short distances. But considering the long distance, Fiber Optic is the best solution in terms of maintenance and the various losses that occur in the electrical environment.

Copper wires are very susceptible to various interferences. One that is the worst case scenario is EMP effects on electrical media such as copper wires. With a burst of electromagnetic radiation from an explosion or a suddenly fluctuating magnetic field… the resulting electric and magnetic fields can couple with electrical/electronic systems to produce damaging voltage and current spikes. This results in probable damage to electronic equipment and electrical infrastructure.

Therefore, especially the most critical applications or mission critical departments need to consider these effects. Care must be taken when designing an organization’s network. This should also include your electrical cables that come outside of your organization. To eliminate EMP effects on electrical cables, EMP filters must be used depending on the ability to isolate your standby equipment.

Let me rule out some of the more esoteric differences.

* Copper interfaces and modules are more common and possibly cheaper.

* Copper interfaces generally cost higher oversubscription rates for ASICs compared to fiber, primarily due to port densities on modules or cards.

* Physical separation between copper plant and fiber plant is often desired to differentiate between client/server and network infrastructure traffic. Separate pipelines are often (or should be) used.

* Higher bandwidth technologies are available over fiber before copper catches up.

In addition to being dramatically cheaper (multimode fiber can double the cost of a workstation), copper is the only realistic means of implementing Power over Ethernet, which can also deliver savings in a number of ways.

Fiber is great for backbones if it’s cost-effective. Ultimately, if the business need for fiber outweighs the cost, go for fiber. The same applies to free space, although the costs with free space are more administrative than equipment.

I would default to 10/100/1000 copper and answer questions about bandwidth, EM interference, and fiber and RF user motility as cases arise. A good example of a need for fiber is in applications where cables run through machinery, such as in a CAD/CAM/JIT shop. Jobs enter and pass into the hopper which is on a machine next to a large lathe. Also in power production you will want the fiber to pass some distance from the turbines.

A strong fundamental understanding of engineering principles will not lead you down the wrong path. And to the question of the distance with the copper, you can always install low-consumption ARM microservers configured as routers and repeaters that are powered by the ethernet cables themselves.

Basically, it all depends on the size of the budget. Particularly in the sense of local area networks… where the options are wireless or wired.

Fiber is the ideal option if your budget allows due to the low cost of expanding bandwidth in the future. With glass, you pay for future expansion in advance.

Now, let’s focus on WiFi/WiMax v. COE.

1. Do you have competent staff who can support access points, intrusion detection and mitigation, and general wireless security?

2. Do you have an existing EOC infrastructure? How old, how capable?

3. Multi-building campus? Hybrid technologies are better here. A combination of glass, copper and wireless.

In short, the answer is “It depends”.

If I had an existing plant, with patch panels and switches, I’d keep them running as long as possible. Not all PCs need Gigabit Ethernet access.

However, it would install redundant fiber rings connecting all the closets and data centers.

For assistance in navigating all the decisions to arrive at the best solution for your network… I suggest the free help available through DS3-Bandwidth.com